Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations

Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations

Author Durigon, A. M. Google Scholar
Borja-Oliveira, Caroline Ribeiro de Google Scholar
Dal Belo, Cháriston André Google Scholar
Oshima-Franco, Yoko Google Scholar
Cogo, José Carlos Google Scholar
Lapa, Antonio José Autor UNIFESP Google Scholar
Souccar, Caden Autor UNIFESP Google Scholar
Rodrigues-Simioni, Lea Google Scholar
Institution Universidade Estadual de Campinas (UNICAMP)
Universidade do Vale do Paraíba Instituto de Pesquisa e Desenvolvimento
Universidade Federal de São Paulo (UNIFESP)
Abstract The pharmacological effects of Bothrops neuwiedi pauloensis venom on mouse phrenic nerve-diaphragm (PND) preparations were studied. Venom (20 mug/ml) irreversibly inhibited indirectly evoked twitches in PND preparations (60 ± 10% inhibition, mean ± SEM; p<0.05; n=6). At 50 mug/ml, the venom blocked indirectly and directly (curarized preparations) evoked twitches in mouse hemidiaphragms. In the absence of Ca2+, venom (50 mug/ml), produced partial blockade only after an 80 min incubation, which reached 40.3 ± 7.8% (p<0.05; n=3) after 120 min. Venom (20 mug/ml) increased (25 ± 2%, p< 0.05) the frequency of giant miniature end-plate potentials in 9 of 10 end-plates after 30 min and the number of miniature end-plate potentials which was maximum (562 ± 3%, p<0.05) after 120 min. During the same period, the resting membrane potential decreased from - 81 ± 1.4 mV to - 41.3 ± 3.6 mV 24 fibers; p<0.01; n=4) in the end-plate region and from - 77.4 ± 1.4 to -44.6 ± 3.9 mV (24 fibers; p<0.01; n=4) in regions distant from the end-plate. These results indicate that B. n. pauloensis venom acts primarily at presynaptic sites. They also suggest that enzymatic activity may be involved in this pharmacological action.
Keywords giant MEPPs
myotoxicity
neurotoxicity
presynaptic action
Language English
Sponsor Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Date 2005-03-01
Published in Journal of Venomous Animals and Toxins including Tropical Diseases. Centro de Estudos de Venenos e Animais Peçonhentos - CEVAP, Universidade Estadual Paulista - UNESP, v. 11, n. 1, p. 22-33, 2005.
ISSN 1678-9199 (Sherpa/Romeo)
Publisher Centro de Estudos de Venenos e Animais Peçonhentos - CEVAP, Universidade Estadual Paulista - UNESP
Extent 22-33
Origin http://dx.doi.org/10.1590/S1678-91992005000100004
Access rights Open access Open Access
Type Article
SciELO ID S1678-91992005000100004 (statistics in SciELO)
URI http://repositorio.unifesp.br/handle/11600/2440

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